Disappointment

Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Disappointment Lake on July 30th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this lake. During the summer, Cisco require a layer of oxythermal habitat that contains water temperatures below 21.2 degrees C (70.2 degrees F) and dissolved oxygen concentrations above 3.0 mg/L. Based on the profile from the deepest basin (maximum sampled depth 52.5 feet), the water temperature decreased below 21.2 degrees C (70.2 degrees F) at 14.7 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 21.0 feet at the time of sampling. The thickness of this layer of water in the water column was 6.3 feet, indicating that oxythermal habitat was present for Cisco. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 15.7 degrees C (60.3 degrees F). TDO3 values cooler than 21.2 degrees C (70.2 degrees F) indicate that oxythermal conditions were suitable for Cisco at the time of the survey. Data collected by the Minnesota Department of Natural Resources during the late summer period of maximum oxythermal stress (July 26th to Aug 24th) in 2024 also indicates suitable oxythermal habitat, with the least favorable conditions recorded in 2024 when the suitable oxythermal habitat layer was 2.4 feet thick. When adequate oxythermal habitat is unavailable, Cisco are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Disappointment Lake on July 30th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this lake. During the summer, Cisco require a layer of oxythermal habitat that contains water temperatures below 21.2 degrees C (70.2 degrees F) and dissolved oxygen concentrations above 3.0 mg/L. Based on the profile from the deepest basin (maximum sampled depth 52.5 feet), the water temperature decreased below 21.2 degrees C (70.2 degrees F) at 14.7 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 21.0 feet at the time of sampling. The thickness of this layer of water in the water column was 6.3 feet, indicating that oxythermal habitat was present for Cisco. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 15.7 degrees C (60.3 degrees F). TDO3 values cooler than 21.2 degrees C (70.2 degrees F) indicate that oxythermal conditions were suitable for Cisco at the time of the survey. Data collected by the Minnesota Department of Natural Resources during the late summer period of maximum oxythermal stress (July 26th to Aug 24th) in 2024 also indicates suitable oxythermal habitat, with the least favorable conditions recorded in 2024 when the suitable oxythermal habitat layer was 2.4 feet thick. When adequate oxythermal habitat is unavailable, Cisco are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

Temperature and dissolved oxygen (DO) measurements were collected from the deepest basin in Disappointment Lake on July 30th, 2025, to evaluate the quantity and quality of cold, oxygenated water (i.e., oxythermal habitat) available to Cisco, also known as Tullibee, the most sensitive coldwater species present in this lake. During the summer, Cisco require a layer of oxythermal habitat that contains water temperatures below 21.2 degrees C (70.2 degrees F) and dissolved oxygen concentrations above 3.0 mg/L. Based on the profile from the deepest basin (maximum sampled depth 52.5 feet), the water temperature decreased below 21.2 degrees C (70.2 degrees F) at 14.7 feet and the dissolved oxygen concentration decreased to 3.0 mg/L at 21.0 feet at the time of sampling. The thickness of this layer of water in the water column was 6.3 feet, indicating that oxythermal habitat was present for Cisco. Further, the temperature at which dissolved oxygen decreased to 3.0 mg/L (i.e., TDO3, a single variable to characterize oxythermal habitat) was 15.7 degrees C (60.3 degrees F). TDO3 values cooler than 21.2 degrees C (70.2 degrees F) indicate that oxythermal conditions were suitable for Cisco at the time of the survey. Data collected by the Minnesota Department of Natural Resources during the late summer period of maximum oxythermal stress (July 26th to Aug 24th) in 2024 also indicates suitable oxythermal habitat, with the least favorable conditions recorded in 2024 when the suitable oxythermal habitat layer was 2.4 feet thick. When adequate oxythermal habitat is unavailable, Cisco are squeezed into unfavorable, warmer water conditions and experience higher levels of stress.

Based on Minnesota DNR survey data, anglers target Walleye, Northern Pike, Smallmouth Bass, Largemouth Bass, and Yellow Perch in Disappointment. See the full species list above for catch rates, size structure, and quality scores.

We don't have a confirmed public access point on record for Disappointment. Check the DNR LakeFinder page for current access details before you go.

Disappointment has a maximum depth of 54 feet, per Minnesota DNR data.

The most recent Minnesota DNR survey data for the main sport fish in Disappointment is from 2024.

No invasive species are on record for Disappointment in Minnesota DNR data. Always clean, drain, and dry your equipment to help keep it that way.

No — Disappointment has no lake-specific regulations in the 2026 Minnesota DNR regulations, so statewide Minnesota limits apply. The statewide walleye and sauger limit is: 6 combined, not more than one walleye over 20". Verify current rules with the Minnesota DNR before keeping fish.